Proposal of Dual-Mode Adiabatic 3-dB Coupler via Shortcuts to Adiabaticity at Wavelength 2.1 µm

Dual-mode adiabatic 3-dB coupler is proposed for wavelength 2.1 µm. Reduction of the device length is achieved by shortcuts to adiabaticity. The proposed device provides low insertion loss, power imbalance, and phase error for TE0 and TE1 modes in spectral range of 2.06–2.14 µm.